We have been studying neuroglioma brain cancer cells that grow in culture. We have found, by immunohistochemistry, that calretinin is present in the neuroglioma cells. By gel electrophoresis and immunoblotting, we have also observed a positive band of both calretinin and calbindin. This would suggest that both these calcium binding proteins coexist in these neuroglioma cells. By ribonuclease protection assay we have revealed the presence of calretinin mRNA. We speculate that calretinin may be involved in cell proliferation of these cancer cells.